Abstract:In order to accomplish peeling off between castor capsule and castor bean, the bulk loads and direction are very important. Based on the measurement and analysis of castor capsule physical properties, the mechanical properties of castor capsule loaded in different directions have been analysed by use of contact mechanics. The results showed that the location of broken shell occurred at the top of castor capsule raphe when pressure load was on the top of castor capsule. In this state, the mesoearp was cracked inside and castor bean emerged from the shell; when pressure load was imposed on castor capsule waist, the location of broken shell occurred at the two ends of mesocarp raphe and four sides lining of castor capsule. In this state, the castor bean emerged from castor capsule shell. The results proved that the forces of top castor capsule were larger than the forces of castor capsule waist